Re: [PATCH 0/2] SMMU v3 CMDQ fix and improvement

[Jacob Pan]

Hi, any thoughts on these?

@Jason @Nicolin 

On Wed, 24 Sep 2025 10:54:36 -0700
Jacob Pan <jacob.pan@xxxxxxxxxxxxxxxxxxx> wrote:

> Hi Will et al,
> 
> These two patches are derived from testing SMMU driver with smaller
> CMDQ sizes where we see soft lockups.
> 
> This happens on HyperV emulated SMMU v3 as well as baremetal ARM
> servers with artificially reduced queue size and microbenchmark to
> stress test concurrency.
> 
> Thanks,
> 
> Jacob 
> 
> 
> Alexander Grest (1):
>   iommu/arm-smmu-v3: Improve CMDQ lock fairness and efficiency
> 
> Jacob Pan (1):
>   iommu/arm-smmu-v3: Fix CMDQ timeout warning
> 
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 85
> +++++++++------------ 1 file changed, 35 insertions(+), 50
> deletions(-)
>